A meta-analysis of SARS-CoV-2 seroprevalence studies in kids found that at that start of the Omicron surge, 50% to 70% of children were still susceptible and that levels of earlier infection were higher in lower-income countries and in ethnic minority groups. An international research team published their findings yesterday in eClinicalMedicine.
The researchers wrote that it's important to look at patterns of seroprevalence in kids, which are the most undervaccinated group, with greater numbers needing critical care in the wake of the Omicron variant. For their study, they included 247 studies that included 757,075 children across 70 countries. They pointed out that only two of the studies included samples from early 2022, which doesn't adequately cover Omicron waves.
The team found that seroprevalence increased over time and varied by geographic region. Their seroprevalence estimate averaged 7.3% for the first COVID-19 wave, 37.6% for the fifth wave, and 56.6% for the sixth wave. They found no sex difference in the risk of contracting the virus.
The highest seroprevalence levels were among children in South East Asia and Africa regions, with the lowest in the Western Pacific region. Estimates were higher in older children, those in lower-income countries, and those in ethnic minority groups. For example, Hispanic children had a higher risk of infection than White children.
"Considering the highly contagious nature of the new SARS-CoV-2 variants, developing a new generation of vaccines that is effective against a wide range of variants and expanding vaccine coverage for children and adolescents must be a priority, particularly for those in underprivileged settings and those with minority ethnic backgrounds," the group wrote.